This invention relates to an anti-howl back device for prevention of an oscillation phenomenon present in various audio systems, cable or wireless communication systems and the like, caused by an acoustic feedback of an output signal from an output means to an input means.
Soundwaves or vibrations radiated by a speaker, if fed into a microphone or especially an input amplifier stage, causes the generation of a continuous vibration having certain frequency. Not only soundwaves or vibrations but also any of other type of signal, if an acoustic feedback from an output means to an input means occurs, an oscillating phenomenon will likewise occur.
Such phenomenon brings about inconveniences at various occasions. For example, in sound reinforcement systems including microphones, amplifiers, etc. used at a concert, such that the least carelessness in turning a microphone on often immediately causes an acoustic feedback of the output from speakers to the microphone resulting in an oscillation phenomenon. It is also well known that simultaneous talk over a cable or wireless communication system is very difficult because of such an oscillation phenomenon as caused by an acoustic feedback of an output signal.